Poinsettias like lots of bright, indirect sunlight and prefer humid conditions (so you may want to mist your plant if your home is very dry due to heating or climate). As for watering, let the soil dry out between watering. The soil should be dry to the touch. Also, be sure not to let the plants pot stand in water at the plants base or saucer(A layer of pebbles in the bottom of the tray keeps the plant out of the water and increases the humidity around the plant). Poinsettias are sensitive to extreme temperature, so don�t place your plant next to a heater or near a drafty window or doorway. A daytime temp of around 65 degrees and nights around 60 degrees will provide perfect conditions for your poinsettia. Whitefly can sometimes be a pest for this plant; check your purchase closely. If you pick it up, and things fly, and they're white, well, there it is. Pretty easily taken care of with insecticidial soap or my favorite indoor pesticide, pyrethrine (made of daisies; it's organic and safe if you don't drink it).